Conventional toothbrushes have cleaning elements that extend from a rigid head. Teeth and gums by nature have a complex intricate contour. Due to the rigid nature of the attachment of the cleaning elements to the head of the toothbrush, the orientation of the cleaning elements is not flexible and thus conventional toothbrushes do not provide optimal cleaning of teeth and gums. Conventional toothbrushes therefore have great difficulty in contacting areas of the teeth located at a greater distance from the head, including interproximal spaces between teeth.
Efforts have been made to improve tooth cleaning performance by developing special filaments with unique physical characteristics. One such exemplary filament has a cross-section profile that changes along the longitudinal axis of the filament. This filament has a square cross-section and is twisted so that the square cross section is rotated about the filament's central axis. When a sufficient amount of these twisted filaments are run across the teeth, they provide a unique, scrubbing mouth feel to the user. Other examples of filaments with changing profiles along the central axis are “crinkled” or “wavy” filaments, which have varying profiles like a sine wave.
Analysis of conventionally tufted toothbrushes with twisted “spiral” filaments revealed that tufts with the twisted spiral filaments have a tendency to appear “bushy” at their tips. This “bushiness” is not a desirable characteristic, since this appearance is perceived to indicate that the toothbrush is worn. However, this “bushiness” merely indicates the fact that the tips of the filaments no longer appear as discreet groups of filaments.
Improvement to the existing technology is thus desirable.